Lau 1996.

Methods	28 months, RCT parallel design, randomized using computer‐generated random numbers by the block method, concealment of allocation using sealed envelopes, outcome assessment was made by two assessors (not stated if independent from the treating team and blind) for pain evaluation and by the treating team for activity, work return evaluation and complications, available to follow‐up at 4 weeks: 73% for laparoscopic group versus 69% for open surgery group but all live patients available at 8 weeks for gastroscopy, to intention‐to‐treat analysis.
Participants	93 patients (48 for laparoscopic group and 45 for open surgery group). Sex: 79 men/14 women Mean age 47.8 to 52.3 years Site of perforation: duodenum (76), juxtapyloric (11), gastric (6) Size of perforation 1‐25 mm Age of inclusion not reported, but probably adults. Inclusion criteria: Clinical diagnosis of perforated peptic ulcer made by the surgeon and confirmed at the operation room. Exclusions criteria: Complicated ulcers that required definitive surgery (criteria not stated) Bleeding ulcer Previous abdominal operations Serious associated cardiopulmonary diseases Clinically sealed perforation. Severity assessed by APACHE II score. Median 6.
Interventions	Intravenous cefuroxime 750 mg and metronidazole 500 mg were given at the time of induction and for the first postoperative day. For postoperative analgesia, patients were prescribed pethidine 1 mg/kg every 4 hours as required. Upper midline incisions were made in patients assigned to open repair. Perforations were repaired with the Cellan‐Jones method or using a rolled piece of gelatin sponge placed in the perforation and secured with fibrin sealant. For laparoscopic repair, pneumoperitoneum was established at 15 mm Hg, and three trocars were introduced and the ulcer was sutured with a piece of omentum and non‐absorbable suture or using a gelatin and fibrin sealant. The number of participating surgeons, the number of cases previously operated by the surgeon and the number of patients operated by each surgeon was not reported. The study divided laparoscopic and open surgery groups in two groups: one repaired with suture and the other repaired with fibrin sealant. We did not consider this distinction to be important and we re‐aggregated the data.
Outcomes	Complications Time of nasogastric aspiration Time of intravenous fluid maintenance Pain assessed with Visual Analogue Scale Conversion rate for laparoscopic group Operation time Analgesic use Time to resume oral diet Length of hospital stay
Notes	Sample size was calculated using the analgesic doses using a previous study made by the same authors.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Computer‐generated blocked random numbers were used"
Allocation concealment (selection bias)	Low risk	"to assign the type of surgery, which was written on a card sealed in a completely opaque envelope. Envelopes were drawn randomly by the senior duty nurse in the operating department"
Blinding (performance bias and detection bias) All outcomes	High risk	"All patients were assessed by the treating team approximately 4 weeks postoperatively in the outpatient clinic"
Incomplete outcome data (attrition bias) All outcomes	Low risk	"At the end of 6 to 8 weeks after surgery, gastroscopy showed that the ulcers had healed for all patients", "Similar proportions of patients with laparoscopic repair (group 1 and 2) and open repair (groups 3 and 4) were available at follow‐up (73% vs. 69%), respectively", "The data for patients who did not attend this first follow‐up visit but who were called back for a check‐up gastroscopy were not included in this analysis because there was a delay of at least 1 month in the recording of these data, which made it less reliable" We believe that lost to follow up at four weeks for measuring returning to work do no affect results of important outcomes for this systematic review.
Selective reporting (reporting bias)	Low risk	Authors reported a second study in 1998 that is consistent with data from this study.
Other bias	Unclear risk	In surgical trials, there is always a bias related with learning curve for the new surgical methods. However, we believe this bias is not present in this trial because experience of surgeons is similar.